/Engine/Source/Runtime/MeshDescription/Public/MeshDescriptionBase.h
Return the vertex instance which corresponds to the given vertex on the given polygon, or INDEX_NONE
[FVertexInstanceID](API\Runtime\MeshDescription\FVertexInstanceID) GetVertexInstanceForPolygonVertex ( [FPolygonID](API\Runtime\MeshDescription\FPolygonID) PolygonID, [FVertexID](API\Runtime\MeshDescription\FVertexID) VertexID ) const